Diabetes on the CCFP exam

Approach

• Check every adult's risk each year. CANRISK, the Canadian diabetes risk questionnaire, is valid from age 40.
• Screen with fasting glucose or A1C (a blood test of average glucose) every 3 years from 40, or at high risk on a risk tool. Very high risk: every 6 to 12 months.
• Test younger or more often for a parent or sibling with type 2, obesity, or African, Arab, Asian, Hispanic, Indigenous or South Asian descent.
• After gestational diabetes: a 75 g glucose tolerance test 6 weeks to 6 months after delivery. Then test every 3 years, or more often.
• No symptoms: repeat a result in the diabetes range on another day. With symptoms of high glucose, one result is enough.
• Do not diagnose with A1C alone in children, pregnancy or suspected type 1 diabetes. Anemia and some hemoglobin variants can mislead it too.
• A child with heavy urine, weight loss or vomiting with fast breathing: check glucose and ketones now, not tomorrow.

Approach

• Adults with type 2: metformin first for most, with healthy eating and activity. Aim for an A1C of 7.0% or less.
• Start insulin at once, with or without metformin, if high glucose has made the patient unwell, whatever the A1C.
• A1C more than 1.5% above target: think about metformin plus a second drug from the start.
• Heart or blood vessel disease: add a sodium-glucose cotransporter 2 (SGLT2) inhibitor or glucagon-like peptide-1 (GLP-1) receptor agonist, even at target. Heart failure or kidney disease: an SGLT2 inhibitor.
• Not at target within 3 to 6 months: raise a dose, swap or add a drug. Look for a cause first, such as infection.
• Frail older people, or repeated severe lows: aim for 7.1 to 8.5%. Sulfonylureas bring more lows and weight gain than newer drugs.
• Youth with type 2: test for diabetes autoantibodies. Up to 10 to 20% with a type 2 picture have them, pointing to type 1.

Approach

• Missed insulin is a main cause of ketoacidosis. When ill, change the insulin dose by the readings rather than stop it.
• Check glucose every 2 to 4 hours. In type 1, check ketones if glucose stays above 14 mmol/L. Blood ketones beat urine ketones.
• Make a written sick-day plan: which drugs to keep or stop, how to change insulin, and when to seek care.
• Low glucose in adults is below 3.9 mmol/L. Early signs: shaking, sweating, pounding heart, hunger. Later: confusion, drowsiness, slurred speech.
• Treat a low with 15 g of fast sugar, such as glucose. Recheck in 15 minutes and repeat if still below 3.9. Then eat.
• An adult who cannot swallow: glucagon 1 mg under the skin or into muscle, or 3 mg in the nose. Call emergency services.

Approach

• Ask what he knows, what worries him and what gets in the way. Build the plan with him.
• Use problem solving and goal setting. Agree on one small, clear goal at a time.
• Teach self-monitoring of glucose, weight or activity, so he sees his own progress.
• Offer group classes with one-on-one follow-up. Together they lower A1C more than either alone.
• Fit the teaching to his culture and reading level. Peer or lay educators can help.
• Offer support between visits: phone follow-up, coaching or peer groups. Involve family if stress at home is a barrier.
• Book follow-up. If A1C is not at target within 3 to 6 months, change the drugs.

Approach

• Kidneys: urine ACR and creatinine for estimated glomerular filtration rate (eGFR), a measure of kidney function, every year. Type 2: from diagnosis. Type 1: from 5 years after onset.
• Diagnose kidney disease only if it persists: 2 of 3 ACRs abnormal over at least 3 months. In adults, abnormal is 2.0 mg/mmol or more.
• In youth, abnormal is over 2.5 mg/mmol. Confirm with a first-morning ACR at least 1 month later. If it stays abnormal over 6 to 12 months, refer to a pediatric kidney specialist.
• Confirmed kidney disease: an ACE inhibitor or angiotensin receptor blocker, up to the top tolerated dose. Not both together. Teen girls need contraceptive counselling.
• Refer to nephrology if ACR stays 60 mg/mmol or more after adding 2 or more add-on drug classes, such as an SGLT2 inhibitor. The add-ons go on top of the ACE inhibitor or receptor blocker. Also refer for eGFR falling fast and under 45, or blood pressure uncontrolled on three drugs, one of them a diuretic.
• Eyes: an eye-care professional screens. Refer sight-threatening retinopathy to an ophthalmologist.
• Feet: examine at least yearly with a 10 g monofilament (a nylon thread that tests feeling), pulses and skin. Send an ulcer or infection to a foot team promptly.

Approach

• Send glucose, electrolytes with the anion gap (a sum that flags hidden acid), creatinine, osmolality (how concentrated the blood is), blood gas and blood ketones (beta-hydroxybutyrate).
• Ketoacidosis usually means pH 7.3 or less, bicarbonate 15 mmol/L or less, anion gap over 12, and ketones. Glucose is usually 14 mmol/L or more.
• A normal glucose does not rule it out on an SGLT2 inhibitor or in pregnancy.
• Negative urine ketones do not rule it out either. Measure blood ketones.
• Find the trigger: new diabetes, missed insulin, infection, heart attack, stroke, trauma or drugs.
• Very high glucose with little acid: think of the hyperosmolar state. Glucose is usually 34 mmol/L or more, osmolality over 320 mOsm/kg, with more fluid loss.
• Any child with new diabetes: check ketones and acid–base status at once.

Approach

• Children: use a pediatric protocol. Brain swelling (cerebral edema) is a greater risk.
• Adults: 0.9% saline at 500 mL/h for 4 hours, then 250 mL/h for 4 hours. Give 1 to 2 L/h in shock.
• Potassium below 3.3 mmol/L: hold insulin until replacement brings it to 3.3 or more. Once urine flows, add potassium to the fluids if it is below 5.0 to 5.5 mmol/L.
• Keep the insulin infusion running until the anion gap closes, not until glucose is normal.
• Treat brain swelling with mannitol or hypertonic saline.
• Before discharge, find the trigger. Missed insulin is a common one.
• Teach a sick-day plan with blood ketone checks. In young people, it cuts emergency visits.